1. Field of Invention
This invention relates to a stone-cutting equipment and, in particular, stone cutting equipment used in an underground quarry.
2. Prior Art
Cutting and removing stone from the ground, particularly from underground quarries, is a difficult and frequently slow task. There are various techniques and types of equipment used to remove large blocks of stone from quarries. One method for removing stone from a quarry is by wedging out the stone using mechanical means employing hydraulics and pneumatics. This method is crude, difficult, time-consuming, and does not result in a smooth-cut surface for the cut stone.
Another method using a wire saw is disclosed, for example, in U.S. Pat. Nos. 3,598,101 and 3,884,212. The wire saw includes an abrasive cutting element, sleeved over an endless flexible wire and a pressure molded-in-place resilient material surrounding the cable and providing a substantially uniform diameter for the endless cutting element. This saw is commonly used in stationery wire saw stands wherein the wire saw is engaged by two sheaves located on either side of the block of stone being sawed. To use such a wire saw when the stone is in place requires drilling into the stone through which the wire is threaded and then reattached. The use of a wire saw in a quarry application is difficult, time consuming and certainly not a preferred method.
A newer method for cutting stone uses a belt-configured saw comprised of a mainframe, a jib movably mounted to the mainframe, and a continuous flexible belt extending around and in-driven engagement with sheaves on the jib. The belt includes a plurality of spaced-apart, abrasive cutting strips extending across the top and sides of the belt. This belt-configured saw employs a grinding action rather than a cutting action to cut the stone. Examples of this belt-configured saw are disclosed, for example, in U.S. Pat. Nos. 4,962,967, 4,945,889, 4,603,678, and 4,181,115. While such saws are useful in cutting stone, they must be attached to a support system to be useful in gallery application.
A device currently in use for the cutting of stone in an underground quarry is a cutter Kerfer type HRU 1100 Underground Cutting Saw System manufactured by Etx. F. Perrier & Cie. It uses a diamond-cutting, 68-link chain which is supported by a hydraulic support structure. However, it is limited to use in underground galleries which are approximately 8 feet in height and approximately 23 feet in width. It is frequently impractical because of its relatively light structure, imprecise hydraulic systems used for movement of the cutting element, and awkward or bulky arrangement with the hydraulic plant and other controls maintained in a separate element, from the cutting element.
Another system similar to the Perrier system, manufactured by Maschinenfabrik Korfmann GMBH of Germany is a Korfman - Stone Cutter Type HSTK-60/Carrara system. Again, as with the Perrier device, it can only be used in chambers which are a maximum of 3 meters in height, 5 meters in width. Further, it can cut to a depth of no more than 2.5 meters. Similar problems are involved in the use of this system as with the Perrier system, including extensive set-up time and awkwardness of the equipment while in use.
There are a number of other devices that have been used for the cutting of very hard materials such as reinforced concrete, stone and the like. Although these tools are not normally used for the cutting of stone in a quarry, they do disclose methods for the cutting of hard materials. See, for example, U.S. Pat. Nos. 4,998,775, 4,986,252, 4,899,720, 4,836,494, 4,756,298, 4,181,115, 3,982,521, 3,722,497, 3,545,422, and 3,360,298.
Although many of the devices disclosed can in some circumstances cut stone from a quarry, none does so efficiently. Each has problems of set-up or use which make it impractical or time-consuming to use. Further, the area of the cut is severely limited.
Therefore, it is an object of this invention to provide a device for the cutting of stone from an underground gallery which permits the stone to be cut along an extended face without resetting of the equipment.
It is a still further object of this invention to provide a device for the cutting of stone from an underground gallery which is easy to set up and can continue to cut stone without extensive loss of time.
It is a still further object of this invention to provide a device for the cutting of stone from an underground gallery wherein the device can cut from the top of the ceiling to the bottom of the floor and from side-to-side along the face of the stone.
It is a still further object of this invention to provide a device containing a saw for the cutting of stone from an underground gallery wherein the device can cut up to at least about 20 feet in height with the depth of cut limited only by the size of the saw.
It is a still further object of this invention to provide a cutting device for the cutting of stone from an underground gallery wherein the cutting device can run on a track, providing virtually limitless travel length, thus reducing significantly set up time.
These and other objects and features of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description, drawing and claims. The description, along with the accompanying drawings, provide a selected example of construction of the device to illustrate the invention.